Colorometric methods of determining fructosamine levels in samples such as blood serum using reagents that produce a color change due to the reducing action of fructosamine are well known as illustrated by John Richard Baker's European Patent No. 0,085,263. The Baker European Patent uses a basic treatment of blood serum with a dye selected from tetrazolium salts, e.g., tetranitro blue, tetrazolium, or preferably nitroblue tetrazolium which, when reduced, changes to a highly colored blue (purple) formazan dye having a broad absorbance peak at about 535 nm. The Baker method uses two color readings with a definite time interval therebetween to develop a kinetic color change which is utilized to calculate from standards the fructosamine level or content. As is well known, kinetic methods are difficult to perform manually with precision, due to the exact timing required.